however, there are occasions when, in an attempt to hold back the forthcoming cavalcade of solid waste matter if same should come on fairly suddenly (say for instance after a particularly strong cup of coffee or two) when restricting the sphincters urethra and anus is necessary in order to make it to the bathroom without spillage

In this situation I find that the anal sphincter relaxes and sheds load immediately upon touching the posterior to the toilet seat but that SOMETIMES the urethral sphincter stays locked until the relaxation moment experienced when leaving the bathroom